1. Technical Field
The invention relates generally to imaging non-visible radiation and/or visible light for an object, and to performing an inspection of the object using the non-visible radiation and/or visible light image(s).
2. Background Art
Numerous imaging devices exist for generating images of objects based on electromagnetic radiation in the visible light spectral band. However, additional information on one or more attributes of many objects can be obtained from imaging electromagnetic radiation having wavelengths that fall above and/or below visible light. For example, infrared light (e.g., thermal radiation) can be imaged to determine the temperature characteristics of the object. Other radiation spectra having non-visible wavelengths that may provide useful information include ultraviolet light, X-rays, radio waves, and the like.
To date, three major technologies are used to detect and/or measure infrared light. A bolometer, which includes an extremely fine wire in an electrical circuit, can measure temperature based on a change in conductance in the wire. When only a particular spectrum of radiation, such as infrared light, is permitted to reach the bolometer, the radiation can be measured. Similarly, a pyroelectric device can measure radiation by exposing a particular type of crystal to a particular spectrum of radiation. Finally, a thermopile, which includes numerous thermocouple elements, can measure radiation based on temperature changes for each element.
Each technology has been used to create an imaging device for infrared light. In particular, a two-dimensional matrix of a selected detection technology can be combined with proper optics to generate a two-dimensional image of radiation in the infrared spectrum. A similar matrix design is used in modern digital cameras for generating visible light images. However, to date, infrared imaging solutions have lagged in both resolution and cost as compared to visible light imaging solutions. As a result, only small resolution infrared imaging systems, e.g., a four-by-four thermopile array, are available for a low price (e.g., less than a few hundred dollars). However, these imaging systems have an insufficient resolution for many applications.
To date, numerous solutions have been proposed that seek to obtain additional resolution from low-resolution images, particularly visible light images. These solutions include a one-pass super-resolution solution, a simple cubic or bilinear resampling, and the like. A more complex solution comprises a longer-term super-resolution approach that attempts to extract data through complex averaging methods from multiple low-resolution images.
Additional information on an object can also be obtained by fusing two or more images. Image fusion combines images from one or more sensing modalities, e.g., infrared light and visible light, into a single presentation that retains the useful and unique information from both modalities. Properly done, an image fusion presentation can be synergistic. That is, the fused presentation allows the viewer to comprehend more of the totality of the object being imaged.
As a result, a need exists for an improved imaging and/or inspection solution that can incorporate imaging of non-visible radiation (e.g., infrared light) in a cost-effective manner. In particular, a need exists for an imaging system and an inspection system and method that generate and use an image based on non-visible radiation of the object.